feather (n.) Look up feather at Dictionary.com
Old English feðer "a feather; a pen," in plural, "wings," from Proto-Germanic *fethro (cognates: Old Saxon fethara, Old Norse fioþr, Swedish fjäder, Middle Dutch vedere, Dutch veder, Old High German fedara, German Feder), from PIE *pet-ra-, from root *pet- "to rush, to fly" (see petition (n.)). Feather-headed "silly" is from 1640s. Feather-duster attested by 1858. Figurative use of feather in (one's) cap attested by 1734. Birds of a feather "creatures of the same kind" is from 1580s.
feather (v.) Look up feather at Dictionary.com
Old English fiðerian "to furnish with feathers or wings," from feðer (see feather (n.)). Meaning "to fit (an arrow) with feathers" is from early 13c.; that of "to deck, adorn, or provide with plumage" is from late 15c. In reference to oars (later paddles, propellers, etc.) from 1740, perhaps from the notion of the blade turned edgewise, or from the spray of the water as it falls off (compare nautical feather-spray, that produced by the cutwater of a fast vessel). The noun in reference to this is from the verb. Meaning "cut down to a thin edge" is from 1782, originally in woodworking. Phrase feather one's nest "enrich oneself" is from 1580s. Related: Feathered; feathering.